1. Field of the Invention
The present invention generally relates to window shades. More specifically, the present invention relates to spring tension mounted window shades.
2. Background of the Related Art
In the home improvement and construction industries, there is a desire to make a window more pleasing to the eye, to provide some type of shade to the sun and to provide privacy, as needed. Windows are available in many different sizes thereby necessitating that the window shade be fit to the window casement at hand. As a result, numerous sizes of window shades must be available to fit a given window. This is particularly problematic in connection with the sale of such shades because different sizes of shades must be available for purchase to fit the different sizes of windows. Windows of uncommon sizes require custom built shades.
In the prior art, there have been many attempts to address the problem of fitting a shade to a window. U.S. Pat. No. 473,990 (Wilkinson) provides such a spring tension shade that includes spring-loaded pads on opposing ends of the shade to frictionally grip the facing sides of a window casement. However, the main body must generally fit within the width of the casement thereby. This device is not intended to fit to a wide range of window sizes. The focus of this invention is simply to removably attach a window shade to a window casement without the use of tools or mounting hardware. U.S. Pat. No. 4,373,569, issued to Barretella, similarly provides for a window shade assembly that can be easily installed and which is held in place by friction.
These prior art assemblies, however, suffer from the disadvantage of being of a substantially fixed length. The play in the spring-biased pads on the opposing ends of the assembly is minimal. As a result, the prior art assemblies are specifically made for installation into a specific sized window casement.
Therefore, there is a desire to provide a single spring tension shade assembly that can be installed into windows of a wide range of sizes. There is a desire to provide to the consumer with a single shade assembly that can be easily adjusted to fit a given window
Another disadvantage of prior art shade rollers is that the holding force exerted by the ends of the assembly is through the roller itself. This means that there is increased friction that keeps the roller from turning freely. As the holding force increases, the force necessary to operate the roller thereby increases making it harder to furl or unfurl the shade. The increase in the force necessary to operate the shade necessitates that the holding force must be increased to keep the shade assembly secure within the window casement.
Therefore, there is a need for a tension shade assembly that minimizes or reduces the forces exerted on the roller itself to prevent the jamming or the rotation of the roller or the dislodgment of the tension shade assembly from the window casement.